The following is a tabulation of some prior art that presently appears relevant:
U.S. PatentsPatent NumberKind CodeIssue DatePatentee4,980,539B11990 Dec. 25Walton6,121,585B12000 Sep. 19Dam6,192,787B12001 Feb. 27Montalto5,148,688B11992 Sep. 22Pimm etal.6,267,110B12001 Jul. 31Tenenboum etal.5,072,095B11991 Dec. 10Hoffman9,186,006B22015 Nov. 17Soule8,274,016B22012 Sep. 25Montana6,870,135B22005 Mar. 22Hamm etal.9,265,371B22016 Feb. 23Glucksman et al.
U.S. Patent Application PublicationsPublication Nr.Kind CodePub. DateApplicant20160183730A12016 Jun. 30Design HMI LLC et al.20120061050A12012 Mar. 5Petrillo et al.
Many people purchase hot beverages “to-go” at coffee shops, convenience stores, espresso stands, and the like. Although there are several types of hot beverages such as coffee, caf latte, tea, chai, etc., at every coffee shop these beverages are commonly served in a container that the purchaser can dispose of after use. These disposable hot beverage containers are frequently made of waterproof cardboard or a paper-based material carrying a plastic lid on top. Many purchasers prefer to drink their beverages at a leisurely pace while walking or traveling on a train or in an automobile. Since such drinks may consist of 12 oz. or more in quantity, it is often desirable to consume them over a period of 15 minutes or more. The problem is that hot beverages cool rapidly in the paper container, and are less desirable or satisfying than when originally purchased.
Containers made of Styrofoam or a foam-based material are occasionally used to serve hot beverages, and may provide some thermal insulation to retard cooling, but many hot-beverage aficionados believe that Styrofoam imparts an unpleasant side-taste to the beverage. In addition, there is widespread and increasing resistance to the use of Styrofoam on environmental grounds. Establishments catering to the serious hot-beverage consumers invariably use the waterproof paper containers.
There is a large variety of insulated containers available, and many people simply transfer their hot beverages from the ubiquitous paper containers to the insulated ones, and thus consume their beverage at their leisure. Some of these containers also have provisions for electrically heating the contained beverage, and are shown by the following: Walton in U.S. Pat. No. 4,980,539 (1990), Dam in U.S. Pat. No. 6,121,585 (2000), Montalto in U.S. Pat. No. 6,192,787 (2001), and Bedi et al. in U.S. Pub No. 20160183730 (2016). These vessels can be quite effective in maintaining and/or heating a beverage to a desired temperature, but they require users to carry the insulated container to the beverage shop or have it available nearby. They also necessitate the user to wash the container after use. The convenience of the paper container, which can be disposed of after the beverage is consumed, is lost.
Similar heating containers exist, but they burn fuel or generate exothermic reactions to provide heat to the contained beverage. Examples of such vessels are shown by Pimm et al. in U.S. Pat. No. 5,148,688 (1992) and Tenenboum et al. in U.S. Pat. No. 6,267,110 (2001). In addition, One Step Ahead/Leaps And Bounds Co. of Lake Bluff, Ill. distributes a commercially available baby-bottle warmer utilizing an exothermic heating element, calling it “Reusable On-The-Go Bottle Warmer,” Item No. 06918. However, all of these aforementioned containers and devices rely on the use of a specialized vessel for containing the hot beverage, and none can be adapted for use with the waterproof paper hot beverage containers presently distributed widely.
Also available are small hotplates designed to keep beverages in a container at or near optimum drinking temperature, as shown in U.S. Pat. No. 5,072,095 to Hoffman (1991). Such hotplates, designed for use on a desk or counter, work well with conventional ceramic or metal beverage containers, but are not very effective when used with the conventional “to-go” paper containers. Since the bottom wall of the beverage-containing part of the container is recessed inside the bottom of its walls, this beverage-containing part does not contact the heated surface of the hotplate. Thus, Hoffman's hotplate is unable to effectively heat beverages contained in conventional waterproof paper containers.
Another approach to prevent hot beverages from cooling involves using phase change material, shown by Petrillo et al. in U.S. Pub. No. 20120061050 (2012). Small capsules of the material are placed directly in a hot beverage to maintain it at a drinkable temperature. However, the user has little control over the preferred temperature, and the user is at risk of swallowing the capsules. Similar to the vessel heaters, cleaning the device after use is also required, since it is surrounded by liquid.
There also exist heating devices that slip over paper hot beverage containers, as shown in U.S. Pat. No. 9,186,006 to Soule (2015), U.S. Pat. No. 8,274,016 to Montana (2012), U.S. Pat. No. 6,870,135 to Hamm et al. (2005), and U.S. Pat. No. 9,265,371 to Glucksman et al. (2016). Although these inventions are able to heat liquid contained in paper beverage vessels, there are some problems with them. For one, the warming sleeve may be uncomfortably hot to touch, and therefore not optimal to hold in one's hand. Second, the apparatus requires an exterior force either by hand or from a horizontal planar surface, such as a table or cup holder, to remain in contact with the hot beverage container. Moreover, the invention described by Soule increases the thickness and length of the beverage-containing vessel. Hamm et al. asserts that it can easily be stowed in a pocket or purse, but it seems too bulky for that. Moreover, those of Soule's and Montana's are not portable and require connecting the apparatus to an external power source, such as a car outlet, while warming the beverage.
A device that serves as a hybrid between a hotplate and a warming sleeve for paper containers would be useful since one such device could offer the wireless convenience and portability of Hamm's yet also deliver heat to the beverage without uncomfortably burning the user's skin.
In conclusion, a diligent search of the patent literature failed to identify any portable device that could be used to warm or maintain the elevated temperature of a beverage ordered “to-go” without eradicating the look and feel of the disposable container.